Polyetheretherketone is one of the most commonly used materials for the production of orthopaedic implants, but the osseointegration capacity of polyetheretherketone is poor because of its bioinert surface, which greatly limits its clinical application. In recent years, scholars have carried out a lot of research on the modification of polyetheretherketone materials in order to improve its osseointegration capacity. At present, the modification of polyetheretherketone is mainly divided into surface modification and blend modification. Therefore, this paper summarizes the research progress of polyetheretherketone material modification technology and its influence on osseointegration from two aspects of surface modification and blend modification for polyetheretherketone materials used in the field of bone repair, so as to provide a reference for the improvement and transformation of polyetheretherketone materials for bone repair in the future.
ObjectiveTo analyze effects of histone demethylase Jumonji-domaincontaining protein 3 (JMJD3) in macrophages in order to provide a new target for treatment of macrophage-related inflammatory reactions, autoimmune diseases, and organ transplantation rejection.MethodThe related literatures of researches on the effects of JMJD3 in the macrophages in recent years were searched and reviewed.ResultsThe macrophages played the important roles in maintaining tissue homeostasis and host response, clearing pathogens and apoptotic cells, and promoting tissue repair and wound healing. The JMJD3 could regulate the balance of M1 and M2 types of macrophages through the different ways and had different effects on the polarization of M2 macrophages when it was stimulated by the different extracellular substances. In some immune diseases and wound repairing, the JMJD3 could not only promote the inflammatory responses, but also polarize the M2 macrophages so as to inhibit the inflammation and promote the tissue repair. Clinically, the JMJD3 expression might be different in the different diseases and its low or high expression both might be involved in the occurrence of diseases.ConclusionHistone demethylase enzyme JMJD3 is involved in macrophage polarization and expression of inflammatory genes, but there are still many problems that require further to be investigated.
Objective To investigate the memory amelioration of the Alzheimer disease (AD)model rat after being transplanted the single neural stem cells(NSC) and NSC modified with human brain-derived neurotrophic factor（hBDNF） gene. Methods Forty SD rats were divided evenly into 4 groups randomly. The AD model rats were made by cutting unilaterallythe fibria fornix of male rats. Ten to twelve days after surgery, the genetically modified and unmodified NSC were implanted into the lateral cerebral ventricle of group Ⅲ and group Ⅳ respectively. Two weeks after transplantation, theamelioration of memory impairment of the rats was detected by Morris water maze. Results The average escaping latency of the group Ⅲ and group Ⅳ (41.84±21.76 s,25.23±17.06 s respectively) was shorter than that of the group Ⅱ(70.91±23.67 s) (Plt;0.01). The percentage of swimming distance inthe platform quadrant in group Ⅲ (36.9%) and in group Ⅳ(42.0%) was higherthan that in the group Ⅱ(26.0%) (Plt;0.01). More marginal and random strategies were used in group Ⅱ.The percentage of swimming distance in the platform quadrant in group Ⅳ was also greater than that in group Ⅲ(Plt;0.05). There were no significant differences in the average escaping latency, the percentage of swimming distance in the platform quadrant and the probe strategy between group Ⅳ and group Ⅰ(Pgt;0.05).More lineal and oriented strategies were used in group Ⅳ. Conclusion The behavioral amelioration of AD model rat was obtained by transplanting single NSC and hBDNF-gene-modified NSC. The effect of the NSC group modified with hBDNF gene is better than that of the groupⅢ.
Objective To review the research progress of promoting the bone formation at early stage by components of the extracellular matrix (ECM). Methods Recent literature concerning the influence of these components on new bone formation and bone/implant contact was extensively reviewed and summarized. Results Coating of titanium or hydroxyapatite implants with organic components of the ECM (such as collagen type I, chondroitin sulfate, and Arg-Gly-Asp peptide) offers great potential to improve new bone formation and enhance bone/implant contact, which in turn will shorten recovery time and improve implant stability. Conclusion The increasing knowledge about the role of the ECM for recruitment, proliferation, differentiation of cells, and regeneration of tissue will eventually deal to the creating of an artificial ECM on the implant that could allow a defined adjustment of the required properties to support the healing process.
ObjectiveTo summarize the related research progress of antibacterial modification of orthopaedic implants surface in recent years. Methods The domestic and foreign related literature in recent years was extensively consulted, the research progress on antibacterial modification of orthopaedic implants surface was discussed from two aspects of characteristics of infection in orthopedic implants and surface anti-infection modification. Results The orthopaedic implants infections are mainly related to aspects of bacterial adhesion, decreased host immunity, and surface biofilm formation. At present, the main antimicrobial coating methods of orthopaedic implants are antibacterial adhesion coating, antibiotic coating, inorganic antimicrobial coating, composite antimicrobial coating, nitric oxide coating, immunomodulation, three-dimensional printing, polymer antimicrobial coating, and “smart” coating. Conclusion The above-mentioned antibacterial coating methods of orthopedic implants can not only inhibit bacterial adhesion, but also solve the problems of low immunity and biofilm formation. However, its mechanism of action and modification are still controversial and require further research.
Objective To observe the expressions of DNA methyltransferases (DNMTs) 1, 3a and 3b in retinoblastoma (RB). Methods Sixty-two RB samples and six normal retinas were studied, including 17 poorly differentiated and 45 well differentiated samples; 16 invasive and 46 non-invasive samples. The expressions of DNMT1, 3a, and 3b, and Ki-67 were detected using immunohistochemical analysis. Brown staining of nuclei was considered to represent the positive stain for DNMT1, 3a and 3b, and ki-67, blue staining as negative. The level of high expression of nuclear staining was, positive cells in DNMT1ge;65%, in DNMT3age;60% and in DNMT3bge;40%. The correlations of DNMT1, 3a and 3b expression in RB samples, and MIB-1 labeling index were analyzed. Results Viewed under the light microscope, negative expressions of DNMT1, 3a and 3b were demonstrated in normal retinas, however, positive expression was observed in RB samples, with 100% in DNMT1, 98% in DNMT3a and 92% in DNMT3b. Comparing well differentiated RB samples with poorly differentiated samples, significant differences were found in high expression of DNMT1 (chi;2=12.57,P＜0.05) and DNMT3a (chi;2=10.54,P＜0.05); also in the positive cells of DNMT1 (U=179,P＜0.05) and DNMT3a (U=198,P＜0.05). No significant difference was found comparing high expression (chi;2=1.5,P＞0.05) and positive cells (U=307,P＞0.05) of DNMT3b. When comparing invasive tumor tissues with non-invasive tumors, significant differences were shown between high expression (chi;2=4.72,P＜0.05) and positive cells comparing DNMT1 (U=236,P＜0.05). No significant difference was shown in high expression (chi;2=3.53,0.84; P＞0.05) in DNMT3a and DNMT3b, or in comparison with positive cells (U=338,257;P＞0.05). The expression of DNMTs was positively correlated with the MIB-1 labeling index in RB tissues (R2=0.554,0.376,0.219;P＜0.05). Conclusion There are high expressions of DNMT1,3a,and 3b in RB.
Objective To summarize the research progress of biocompatibility and surface modification of nickel titanium shape memory alloys (Ni-Ti SMA). Methods The relative researches about Ni-Ti SMA at home and abroad were reviewed, collated, analyzed, and summarized. Results At present, Ni-Ti SMA as an internal fixation material has been widely used in clinic. It has the following advantages: the super elasticity, the shape memory characteristic, the good wear resistance, and the strong corrosion resistance. It also can effectively avoid the internal fixator rupture caused by stress shielding. After surface modification, the biocompatibility of Ni-Ti SMA has been improved. Conclusion The Ni-Ti SMA is the most promising alloy material for the long-term internal fixator because of its excellent material properties.
ObjectiveThe antibacterial properties of porous medical implant materials were reviewed to provide guidance for further improvement of new medical implant materials.MethodsThe literature related to the antibacterial properties of porous medical implant materials in recent years was consulted, and the classification, characteristics and applications, and antibacterial methods of porous medical implant materials were reviewed.ResultsPorous medical implant materials can be classified according to surface pore size, preparation process, degree of degradation in vivo, and material source. It is widely used in the medical field due to its good biocompatibility and biomechanical properties. Nevertheless, the antibacterial properties of porous medical implant materials themselves are not obvious, and their antibacterial properties need to be improved through structural modification, overall modification, and coating modification.ConclusionAt present, coating modification as the mainstream modification method for improving the antibacterial properties of porous medical materials is still a research hotspot. The introduction of new antibacterial substances provides a new perspective for the development of new coated porous medical implant materials, so that the porous medical implant materials have a more reliable antibacterial effect while taking into account biocompatibility.
The rutile structure titanium oxide (Ti-O) film was prepared on the pure titanium material TA2 (99.999%) surface by the magnetic filter high vacuum arc deposition sputtering source. The method can not only maintain the material mechanical properties, but also improve the surface properties for better biocompatibility to accommodate the physiological environment. The preparation process of the Ti-O film was as follows. Firstly, argon ions sputtered to the TA2 substrate surface to remove the excess impurities. Secondly, a metal ion source generated Ti ions and oxygen ions by the RF discharge. Meanwhile a certain negative bias was imposed on the sample. There a certain composition of Ti-O film was obtained under a certain pressure of oxygen in the vacuum chamber. Finally, X-ray diffraction was used to research the structure and composition of the film. The results showed that the Ti-O film of the rutile crystal structure was formed under the 0.18 Pa oxygen partial pressure. A Nano scratch experiment was used to test the coating adhesion property, which demonstrated that the film was stable and durable. The contact angle experiment and the platelet clotting experiment proved that the modified surface method had improved platelet adhesion performance, and, therefore, the material possessed better biocompatibility. On the whole, the evaluations proved the modified material had excellent performance.
【Abstract】 Objective To evaluate the biocompatibil ity of the sheep BMSCs cultured on the surface of photografting modified copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate(PHBV). Methods BMSCs were isolated from bone marrow of the posterior il iac crest of a 6-month old sheep by whole marrow adherent culture method. The 3rd passage BMSCs were seeded onto modified PHBV and conventional PHBV films, or three-dimension scaffolds. Cell-adhesion rates were calculated by hemocytometer at 1, 2 and 6 hours after seeded. Cell morphology was examined by scanning electron microscope when the BMSCs were cultured for 3 days, 1 week and 3 weeks. Cell cycle was analyzed by flow cytometry at 5 days after seeded. The content of protein in BMSCs was determined by BCA assay and the content of DNA was quantified by Hoechst 33258 assay at 4, 8 and 12 days after seeded. Results At 1 hour after seeded, cell-adhesion rate on modified PHBV films (52.7% ± 6.0%) was significantlyhigher than that of conventional PHBV films (37.5% ± 5.3%) (P lt; 0.05); At 2 and 6 hours after seeded, cell-adhesion rate of modified PHBV films was similar to that of PHBV films (P gt; 0.05). The surface of modified PHBV film was rougher. In the early culture stage, more cells adhered to modified PHBV and the cells displayed much greater spreading morphology. Furthermore, ECM on modified PHBV were richer. There were no significant differences between the trial team and the control on the cell cycle and the content of DNA and protein of BMSCs (P gt; 0.05). Conclusion Photografting modification on PHBV can promote BMSCs’ adhesion and enhance their biocompatibil ity.